CDC Warns of Deadly Tick-Borne Illness in People Traveling to Mexico

By Dennis Thompson HealthDay Reporter  |  Copyright © 2023 HealthDay. All rights reserved.

MONDAY, Dec. 11, 2023 (HealthDay News) -- An outbreak of deadly tick-borne disease is occurring among people who’ve recently been to Baja California in Mexico, the U.S. Centers for Disease Control and Prevention warns.

Three out of five patients have died from infection with Rocky Mountain spotted fever (RMSF), the CDC said in a health advisory issued Friday. All were treated in southern California hospitals.

All five patients had traveled to the Baja city of Tecate within two weeks of their illness, the CDC added. The cases have occurred since late July.

Spread by brown dog ticks, RMSF can be fatal within days unless an infected person is treated early with the antibiotic doxycycline, the CDC noted.

Half of all people who die from RMSF succumb within eight days of illness onset.

The CDC is urging doctors to start suspected RMSF patients on doxycycline as quickly as possible, particularly if a person develops early symptoms and has recently traveled to northern Mexico.

“If RMSF is suspected, initiate treatment with doxycycline immediately. Do not delay treatment pending laboratory confirmation. Early treatment saves lives,” the CDC stressed.

Symptoms can be relatively mild and nonspecific during the first four days of illness, and can include fever, headache, GI problems, abdominal pain, muscle pain, rash and swelling around the eyes and the back of the hands, the CDC says.

If left untreated, infection can quickly progress to brain damage, organ failure, breathing problems and coma. Infection can affect  the lungs, heart, kidneys and nervous system.

Four of the five patients were younger than 18, the CDC noted. Children are five times more likely than adults to die from the infection.

Three were U.S. residents, and two were Mexican citizens.

RMSF regularly occurs across northern Mexico and parts of the southwestern United States, the CDC said. Border Mexican states where RMSF is endemic include Baja California, Sonora, Chihuahua, Coahuila and Nuevo Leon.

People who travel to those regions should protect themselves against tick bites by wearing protective clothing, treating their dog for ticks and using insect repellant.

They also should regularly perform thorough tick checks on themselves and their children after any outdoor activities or when around dogs with ticks.

More information

The U.S. Centers for Disease Control and Prevention has more about Rocky Mountain spotted fever.

SOURCE: U.S. Centers for Disease Control and Prevention, news release, Dec. 8, 2023